A Long View of Southern California Water Supply: Perfect Droughts Revisited
A Long View of Southern California Water Supply: Perfect Droughts Revisited
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南加州供水远景：再访完美干旱
DOI：
10.1111/1752-1688.12822
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
E. Bigio
中科院分区：
文献类型：
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作者：
C. Woodhouse;D. Meko;E. Bigio
干旱对干旱和半干旱地区水资源的影响可以通过不同水源地区的供水来缓冲。所有主要水源地区同时发生干旱-或完全干旱-对水资源管理构成最严重的挑战。我们研究了与南加州（SoCal）水资源相关的完美干旱，并对萨克拉门托和科罗拉多河以及SoCal进行了仪器记录和树轮重建。自1906年以来，除了最近的一次，即2012-2015年，已经发生了五次持续两到三年的完全干旱。在过去的六个世纪中，这种数量和持续时间的完全干旱并不罕见。现代时期的完全干旱分布相对均匀，缺乏前几个世纪记录的完全干旱集群。相比之下，12世纪的完全干旱时间更长（长达9年），范围更广。20世纪和21世纪的完美干旱发生在不同的海洋/大气模式、纬向和纬向气流以及ENSO或非ENSO条件下。这三个区域之间存在着多年的一致性，但在过去的六个世纪里，这种一致性有所不同，导致完全干旱的间隔不规则。尽管完全干旱的原因尚不清楚，但考虑到长期的自然变化沿着预计的气候变化，预计未来会发生更频繁和更长时间的完全干旱是合理的。
The impact of drought on water resources in arid and semiarid regions can be buffered by water supplies from different source regions. Simultaneous drought in all major source regions — or perfect drought — poses the most serious challenge to water management. We examine perfect droughts relevant to Southern California (SoCal) water resources with instrumental records and tree‐ring reconstructions for the Sacramento and Colorado Rivers, and SoCal. Perfect droughts have occurred five times since 1906, lasting two to three years, except for the most recent event, 2012–2015. This number and duration of perfect droughts is not unusual in the context of the past six centuries. The modern period stands out for the relatively even distribution of perfect droughts and lacks the clusters of perfect drought documented in prior centuries. In comparison, perfect droughts of the 12th Century were both longer (up to nine years) and more widespread. Perfect droughts of the 20th and 21st Centuries have occurred under different oceanic/atmospheric patterns, zonal and meridional flow, and ENSO or non‐ENSO conditions. Multidecadal coherence across the three regions exists, but it has varied over the past six centuries, resulting in irregular intervals of perfect drought. Although the causes of perfect droughts are not clear, given the long‐term natural variability along with projected changes in climate, it is reasonable to expect more frequent and longer perfect droughts in the future.